Magazine-type heater



May 25, 1948' J. G. GILMOR. 2,442,124

MAGAZINE-TYPE HEATER Filed Jan. 21; 1944 Patented May 25, 1948 Jackson G. Gilmore, Columbus, Ohio Application January 21, 1944, Serial No. 519,158

This invention relates to stoves, furnaces or 6 Claims. (Cl. 126-73) other heating apparatus adapted for burning solid fuels and, more particularly, to coal-burning heaters employing internally disposed magazines or fuel storage hoppers adapted to feed fuel gravitationally to a zone of active combustion. In another of its aspects, the present invention has to do with an improved method for burning solid fuels in magazine-type heating apparatus.

Such' magazine coal-burning heaters have proved to be very satisfactory to most users primarily on account of the relatively small degree of attention required to maintain prolonged operating periods between intervals of fuel replenishment. However, their operation is characteristcally sluggish, particularly when the magazines thereof are charged with fresh quantities of fuel- Under such conditions, the temperature of the apparatus drops and outlet ilue temperatures decrease and as a result of the decreased rate of combustion, normal operation is not restored until a sufficient amount of the new fuel is in a state of active combustion to restore normal temperatures within the h'eater and its associated outlet flue. A study of the operation of the -conventional magazine-type coal-burning heater has revealed that when the fuel is first added, copious quantities of smoke are formed and passed to the outlet flue or chimney. This smoke continues until flame combustion takes place at the upper portion of the magazine, or at the top of the coal body disposed in the magazine. As soon as llame appears at this point, and particularly if the heater has been constructed to admit secondary air, the amount of smoke is materially reduced.

Since smoke is unburned fuel, and its formation indicates inefficient heater operation or fuel combustion, the problem faced in a magazine-type of heater, as here under consideration, is to maintain temperatures in the top of the fuel magazine, or above the coal body therein, which will effect, with adequate lair supply, vthorough and complete combustion of fuel volatiles as th'e same are generated or are released from the coal during its gravitational descent toward the zone of active combustion. In a magazine-type heater, such zone of active combustion is disposed immediately above the grate structure in the lower part of the heater. Such zone is, therefore, disposed in a plane considerably below and spaced from the top or upper portions of the fuel magazine, Furthermore, when large quantities of fresh coal are introduced into th'e magazine, a wide differential exists in the temperatures of the active combustion zone as compared with those which obtain above the coal body.

Various attempts have been made in the prior art to minimize smoke formation in the magazinetype of heater. Generally, such attempts have consisted in diverting a portion of the air obtained from below the grate structure through ilues or passages formed between the refractory lining of the furnace and its metallic outer casing, in order that such diverted air may be delivered to the top of the coal magazine. However, through contact with the metallic casing of the heater and the cooler portions of the refractory lining, the temperature of such' diverted air and coal gases admixed therewith is ordinarily so reduced that by the time the same is introduced into the upper regions of the magazine, the same will not support or produce active flame combustion, with the result that smoke is not consumed until burning gases permeate through the coal body contained in the magazine to a sufcient extent to burn any smoke which at this belated period may be present in the upper portions of the magazine.

Accordingly, it is an object of the present invention to provide an improved magazine-type coal-burning heater. It is another object of the invention to provide a heater of this type in which, at all stages of its active operation, smoke formation is minimized or precluded. It is a further object of the invention to provide such a heater with one or more internally disposed vertically extending restricted passages which are col extensive with' the height of the magaizne and in which pilot combustion of fuel gases takes place throughout the length thereof so that temperatures may be maintained above the coal body within the magazine capable of sustaining flame combustion on the part 0f volatiles released from the fuel body within the magazine. Still, a furth'er object is to provide means for introducing regulated volumes of atmospheric air, independently of the Agrate structure, into the pilot flame passage or passages within the furnace lining, so that fuel gases entering such passages may be admixed with an adequate quantity of air to cause e'ective burning thereof in order that a hot pilot flame may be maintained at all times in the upper regions of the magazine, or immediately above the coal body therein, Again, another obiect is to provide a heater of this type in which the outlets of the llame passage or passages are vso formed andv disposed as to release a pilot name immediately over the coal body as the height of the latter gradually diminishes-as a indicated by the line II-II of Fig. 1;

' tural forms, the

Yof `the casing ,iii are -storage capacity. r'The is formed Y ting openings 2l. v

thef'bonnet is provided with an `outlet flueY 22 .flame passages.

For a further under-standing ofthe invention, reference is' to be had to the following description and the accompanyingV drawings, wherein: n

Fig. 1 is a vertical sectional view taken through a heater provided with a smoke-burning pilotY formed in accordancerwith the present invention; Fig. 2 is a similar view taken on the plane Fig. 3 is a horizontal sectional plane indicated by the line III-III of Fig. 1;

Y Fig. 4. is a detail perspective view disclosing the lining blocks of the heater in which the air and pilot flame'passages areformed. Y Y

v In 'the specific embodiment of my invention illustrated in the drawings which, it will be understood, is but o-ne of Amany possible strucnumeral II] designatesr the outer metallic casing of a heater of the so-called room or space type. The ycasing is formed. at the `bottom thereof with an ash pit II and immediately above the latter with any suitable type of grate structure I2.V In this instance, the grate strucwidth'of the slot is regulated in accordan-ce with the particle or lump size of the coal used in the heater. Hence, `when using ne or Stoker grades of coal, the slot is of minimumwidth and when the larger or lump sizes of coal are used, the slot may be of greater width, `The matter of the width of the slot is of importance View on the ture hasbeen shown as comprising a stationarily Y supported outer ring iwhich carries a perforate Ymanually*movable disk I4. The iront 0f theV pit is provided with an access opening covered, as usual, by a hinged door i5,the latter being provided with shutter controled air-admitting openings -I 6, 1 vSupported on the ring I3 in direct engagement with( the inner surfaces-V Y vertically vdisposed slabs I'i,V

of Vrefractory material of ceramic composition,

Vthe 'latter being so arranged as toY provide the the gra-te structure.

interiorV of the heater above i with a heateinsulating or absorbing lining and, also, to form in the heater a vertical coal-receiving magazine of considerable Vvolume or coal;-

top 'of the casing is pro-l videdwith a heatradiating bonnet I8, in which a coal-admitting opening IS, the latter being normally closed Y which is provided shutter controlled, air-admit- Opposte to the opening I9,

adapted for communicationrwith a chimney or other outlet for wasteproducts of oo n'lbustion.,Y

The particular feature of the present invention resides in providing the refractory lining Aat one side with a plurality Vofsuperimposed vertically arranged lining blocks shown at 23, .24

and 25. VThese blocks cooperate with the slabsV 25 is molded'QeXtruded or otherwise formed V.to

provide 'inwardly Yextending arcuate Walla- 2.9,

which form a part of Vthe passages 26 and 28. The walls terminate in spaced relation with respect .to eachother to'provideV a restricted vertically extending .slotSiL which `is coextensive by a hinged door ZDfinV Each .of the .blocks 23 andV Y the upper end of the passage 26 at least par- ,by the use -0ff'ihe-1efraew1y ses' Yrecesses 3i: Vbe formed by beveling the upper surfaces of the Vcombustion .of the fuel is maintainedfas YVis I in preventing the fuel from entering in Yany substantial degree the ame or pilot passage 2'1, since this passage should bekept open and free from clogging deposits. The blocks 25 each have their upper surfaces formed with inwardly facing Such vrecesses advantageously may Yarcuate walls 29 of theblocks 25, as at 32. VIt willbe noted that these recessesconstitute restricted slots throughY which gases or volatiles distilled from the coal, as the latter approaches the active combustion zone, indicated at/Z, will pass for'admittance into the air supplying pas sage 2 andthe ame passage 2l. Y i

V'Even with the use ofair which entersthe coal body through the granen, there wenig' bef aninsuilcient amount of oxygen in `the gases to` support effective flame combustion through ut the length of the passage 2l. Therefore Y cordance Withjthe present invention, the bottom of the passage Zia with an extraneous air Vinlet 33, in orderthat suflcientvoxygenrwill be introduced into the communicating passagesV 2,5 and 2 to producevactive combustion ofjthe Y fuel gases and volatiles. `IfV kther-heater isasso- YcriatedV with an efcient chimney or waste gas Y outlet, natural draft conditionsmaybe utili ed to regulate and .effect the admittance of air the heater through the inlet '331 However, certain instancesit may be desirable, as in Fig. 3, to associate withthe inlet motor drivenrair fanY or blowerfi,Y The upper ends;

of the passages 2 and 23 are in Vopen'.eoinn1-n-uni' cation Withthe interior .of the Ybo'nriet I8, while tially closed plates=35-` f Y Y. Y Y ,Y In the Operation of .the-heater, coal is intro?! ducediinto the'rnagazine in tl11eus1 ial-rnannerj,` Y Y filling the magazine toa .de Siredheight, A eV tomary, on the grate structure I2, .thefuel being virtually coke, .since as the coal" gravita.-V

A tionally :descends in Ythe magazine, its .temperY Y pliedV by way of the air inlet @Lisa resultiof Y thoroughly Consumed and the generated heat Y the slot 30 and'in', thesepassages,

ature is increasedcausing the removal .of V05`lfq1, .'Y

Vtiles untilby the` timeframe cornbustionl tales place, the fuel assume'sthe-form .of Ycoke lor `d evolatilized coal. Air for the'burning of'this `coke' is suppliedVV through the grate. As At'he'vola are liberated, the same lare drawn into the s ageways 26 and 21 by wayof the recesses .fiel

volatiles are admixed with atmospheric this eddiiio'nel and independent Supply @i fiame .combustion ,offthe volatiles taires,l pla@Y Ythe 'burning gases beine transmitted i Passages 126 and 2i and ini@ theres-ef, azine. Since these burning :gases posse pera ure vin exesefofllw Efwhenfthe Saineare,

n emittdin-io thereon-gratings, of the zi e.

ignitionV ofjsmoke emanating Vfrom :the fuell takes Placegeusing the emekeio, be ,ravi-silva d therefrom efficiently. util-ized by the eater; action taires place :immediately upon theint duction vef Y frsh Goal into the heater/:or furnace and.v @annexation therefore., is inf-avorio@ cene.

5. trast with prior types of heaters wherein the burning of smoke can-be accomplished only after flame has penetrated the fuel body and allowed to emerge into the smoke chamber.

In many types -of bituminous fuels, particularly, the active combustion which takes place immediately over the grate structure is such as to produce a merger of coal or coke particles, forming a fuel cake or bridge whichis virtually impenetrable to the upward ow of gaseous fluids. Such a bridging of the fuel in the present invention isnot deleterious, since the gases below such a bridge may readily enter the lower portions of the passages 26 and 2l. Horeover, I have observed that as a result of the high temperatures in the passage 21 and its communicating slot 30, the solid fuel immediately contiguous to the slot 30 is also burned to such degree that the samefis readily pervious to the passage of gases, thus overcoming the effects rof coal fusion or bridging The operation of the heater remains the same regardless of the amount of coal introduced into the magazine at any one time, Thus the magazine may be but half filled with fuel, and yet the smoke consuming operation remains the same, or it may be filled to any` other fractional part of its total holding capacity with corresponding operation.

My improved heater has been designed to consume efficiently the most diflicultly burned types of coal, as for instance high volatile stolzer grades of bituminous coal, giving satisfactory operation, although, of course, coal having better composition characteristics may be more advantageously employed.

It will be noted that the passages 26, 21 and 28 are formed wholly in the refractory lining and are therefore spaced from the heatradiating casing of the heater, thus maintaining high temperatures on the part of the consumable gases traveling through these passages and minimizing heat loss therefrom. While but a single set of the blocks 23, 24 and 25 have been illustrated, it will be understood that one or more sets of these blocks may be used, depending upon the size and heat capacity of the heater or furnace. Preferably, the blocks 23, 24 and 25 are separately formed merely for convenience in manufacture and assembly. However, it is obvious that said blocks may be providedin a single unit if desired.

By the use of the slot or slots 30, the coal immediately contiguous thereto will burn, thus producing localized combustion of the fuel vertically of the height of the fuel body in the magazine,

Iovercoming the caking or bridging effect which takes place immediately over the zone of active combustion in conventional types of magazine fed heaters. When a plurality of the slots I9 are used, spaced equidistantly around the inside of the magazine or heater, such localized combustion gradually progresses toward the axial center of the magazine, thus causing the coal to gradually settle on the grate structure as it is being consumed and avoiding the need of positively forcing the coal downwardly toward the grate structure by the use of a manually wielded poker or the like in order to disintegrate caked fuel. The ash produced by my heater is characterized by its very ne andlightweight form, the same readily passing through the openings in the grate structure and into the underlying pit. With respect to the recesses 3|, it will be noted that the same are normally closed by the pressing of the fuel body against the surfaces of the relfractory lining. Therefore, fuel gases or air normally tend to travel lengthwise of the passages 2li and Z'Iuntil the top of the coal body is reached, at which time the gases exit through the recesses. However, this action may vary from time to time when pressure differences exist on opposite sides of the recesses. Such dilferences, however, have not proved to be of any practical importance.

My improved heater has the advantage of simplicity in its mechanical construction, providing for low cost manufacture. While a so-called room or space heater has been illustrated in the accompanying drawings having a combustion chamber and Afuel magazine formed in accordance with the present invention, nevertheless, it will be understood that said combustion chamber and magazine may be embodied in many different types of heaters or furnaces having various control devices well known in the art and I therefore reserve the right to employ my invention in all styles of heaters in which the principles of construction and combustion above set forth may be used advantageously.

I claim:

l. Apparatus for burning solid fuel having an outer casing, a grate structure, a fuel receiving magazine above said grate structure, a ceramic lining for said magazine, and a bonnet above said lining, that improvement which comprises: a vertically extending name-conducting flue: formed wholly within the confines of said lining,l said flue extending vertically of the lining from substantially the grate structure to said bonnet and communicating with the interior of said magazine by a vertical slot of restricted width and a plurality of vertically spaced substantially horizontally disposed recesses, and air-supplying means independent of said grate structure for introducing regulable quantities of air into said ue to sustain combustion of fuel volatiles therein.

2. A refractory magazine lining for coal burning heaters comprising superposed groups of ceramic blocks, said blocks being formed to provide a plurality of parallel vertically extending relatively communicating fluid passages, the fronts of said blocks being provided with arcuate extensions, said extensions terminating in relatively spaced order to provide a restricted vertically disposed slot openly communicating with the inwardly formed passages, the blocks at one side of said lining being formed with substantially horizontally disposed recesses constituting restricted ports communicating with the internal passages.

3. Solid fuel burning apparatus comprising a casing, a grate structure in the bottom of said casing, a smoke chamber in the top of said casing, there being a fuel magazine formed within said casing between said grate structure and smoke chamber, a refractory lining for said magazine having formed solely within the connes thereof a plurality of adjacent and vertically extending flue passages, the said passages communicating with each other by a restricted vertically extending slot and one of said passages communicating with the interior of said magazine by a restricted vertically extending slot, additionally in communication with the interior of said magazine by a plurality of vertically spaced and relatively restricted horizontally disposed slots formed in said lining, and means independent of said grate structure for introducing atmospheric air into said passages in quantity suicient to sustain combustion of fuel volatiles,

said ilue passages being Said: volatiles whilst statet tombes: tiert' boeing 'flschergeeble fromisaid Said. Smets chamba@ tot effect. a

e burning ofi chate-bet Y 4- S9131. fuel; burning apaaratus. comprisinsa casing, a grate structure in casing, a fuel-receiving magazine pI0VidCd-` inv Said Casing above Said, grate, Strutture, airefmctt'yl lining .fet Seid message. sais lining em-V boiying 'plurality 0f Vertitally arranged Super-i imposed. blocksv oiV ceramic eQrnpositipn, certain;

of saidbiock beine @meritatamente provide avait- Ot relatively Communicating;vertically. es:

tending Vparallel passages, one off said passages beisst .ttrnrltmmation,v with thel'interioi Ofi said.

magazine. by thevpresence,('.ffffaA restricted vertieallfyV disposed slot'rwhich is substalritiallyv coex-` teneis/etwithV the length of saidvlast-named passage, and theother. of said` passages being in.y

communication with said magazine by the presence of a pliiraiity of substantially horizontally disposed restrictedV ports. formed?. in said blocks,y

ousti'on coalfburningfheaters, eoInprisingYa phi- PffSSaegeS into able .from the combustion passage. into said.

rali'ty of ceramic blocks, adapted to be arranged.

Vin vertically superposedbrdei; Withn the casing ofV an associated heater, certain of said blocks t A 35;. being ,formed internally with parallel vertically extending and relatively communicatingl pas.-

sageways Vfor the. travel of volatile vfuel products, and gases, the blocksfcontainingsaid passageways being formed on oneside with arcnatelextensions,

the vlatter being terminated in spaced relative] order toprovide therebetween a restricted lVertically extending slot communicating with said passageways, andA a" plurality of Sill?S{Q aliiavllypV horizontally Vvextending. recessesvfornied in the bloeks containing said passagewaygsaid recesses constituting restrictedK ports whenl the .blocksJ are in assembled order and Whichcommnnieate with said passageways.

6'. Solid fuel burning apparatus comprisingva casing, a

grate Strutture the bQttQm. of saisi,

casng, a smoke-chambenin the, top, oigthe easing; magazine formed Within saldi: and'v smoke. chamber, a refractom lining. fory said"` magazine,VV embodyineareeion ofsub'stantiallyuniforrncross sectional thicknessand alocalized region` of inotherebei-ng a'fuel; casing` betweeri'sai grate structure creasedY cross sectionala: tlf-knessi seidf region -Ofl ncreasedthilsness heine formed- Wholly Within,

a vertically extending fftielr loticonilaustioripassage, the, latter beine; Sulcistarif,Y` tiallycQextensix/e; withtheffull, height` of. the. magazine and: Communication with the.Y inf v tiited vertically d si of: `rlreased;tbitlsness Der its confines with.v

terior Qftttie latter by posed- Slotl Said; realen ,ing addition. 1y formedqwth a Hue-extending ediately adje..-

` paralleli with Seidl-.passage @faitV` fluter-thereto, passeggiate a lzestristed;

@Qmmumcatina with saidf.

saisiY line; com meeting; with, the. interior 0i Seid magazine Y the. presente'0i-aritmieof;

v"vertically spaced andf horizontally disposedfslotsi and. means.; independent., @said grateY Struttura for ititreducingv atn'iospher-ie` ain, intoA the, lower` portionot saidY flue in qnantitysu'flicient t0sus tain` cornbiistionSi of; fuel4 volatiles;x present inthe `eoriitniistion.n.passage,V said volatilesA While iniV an active state: ofk flame 5 combustionbeing diselbarlge-` magazine.` above4v the. fuel- `contained therein and of smokerand. volatile. -fuel products present therein. Y v

YIAC'KSQPTY G- GII-MQB'E REFERENCEs CITED rflne followingreerences; areV le Ofthis patent:

'Unirse/SEMES PATENTS.

rettitallyextendingslot 1re. chamber .tot eievct actiyeburning.

ofY recordin.r the 

